Several patents describe the use of magnetic acceleration rails to drive projectiles. Many of those patents sequence the switching along with rails to drive the projectile between the rails. Some of the rails are open, some are closed in a cylinder.
Westinghouse U.S. Pat. No. 4,555,972 describes a projectile which is spun by rifling grooves as it is propelled through a bore with a conventional powder charge. Upon reaching the end of the bore, the projectile is accelerated with magnetic energy along conductive rails.
U.S. Pat. No. 2,870,675 describes sequential magnetic energization for acceleration of a projectile. Uniquely, the generator is another projectile. U.S. Pat. No. 4,343,223 describes sequential operations of a magnetic rail gun accelerator.
A need exists for patents which accelerate projectiles from magnetic drives with greater energies and efficiencies.